Lasting B-cell persistence depends on survival signals that are transduced by cell surface receptors. Here, we describe a novel biological mechanism essential for survival and homeostasis of normal peripheral mature B cells and chronic lymphocytic leukemia (CLL) cells, regulated by the heparin-binding cytokine, midkine (MK), and its proteoglycan receptor, the receptor-type tyrosine phosphatase zeta (RPTP). We demonstrate that MK initiates a signaling cascade leading to B cell survival, by binding to RPTP. In mice lacking PTPRZ, the proportion and number of the mature B cell population is reduced. Our results emphasize a unique and critical function for MK signaling in the previously described MIF/CD74 induced survival pathway. Stimulation of CD74 with MIF leads to c-Met activation, resulting in elevation of MK expression in both normal mouse splenic B and CLL cells. Our results indicate that MK and RPTP are important regulators of the B cell repertoire. These findings could pave the way towards understanding the mechanisms shaping B cell survival, and suggest novel therapeutic strategies based on the blockade of the midkine/RPTP-dependent survival pathway.
The cytokine midkine and its receptor RPTPζ regulate B cell survival in a pathway induced by CD74.
Age
View SamplesChronic lymphocytic leukemia (CLL) is characterized by the accumulation of CD5+ B lymphocytes in peripheral blood, lymphoid organs and BM. The main feature of the disease is accumulation of the malignant cells due to decreased apoptosis. CD84 belongs to the Signaling Lymphocyte Activating Molecule (SLAM) family of immunoreceptors, and has an unknown function in CLL cells. Here, we show that the expression of CD84 is significantly elevated from the early stages of the disease, and is regulated by macrophage migration inhibitory factor (MIF) and its receptor, CD74. Activation of cell surface CD84 initiates a signaling cascade that enhances CLL cell survival. Both immune-mediated neutralization or blockade of CD84 induce cell death in vitro and in vivo. In addition, analysis of samples derived from an on-going clinical trial, in which human subjects were treated with humanized anti-CD74 milatuzumab shows a decrease in CD84 mRNA levels milatuzumab-treated cells. This downregulation was correlated with reduction of Bcl-2 and Mcl-1 message. Thus, our data show that overexpression of CD84 in CLL is an important survival mechanism that appears to be an early event in the pathogenesis of the disease. These findings suggest novel therapeutic strategies based on the blockade of this CD84-dependent survival pathway.
CD84 is a survival receptor for CLL cells.
Disease
View SamplesMulticiliated cells are crucial for fluid and ion transport in epithelia of a variety of organs and their impaired development and function are seen in human diseases affecting the brain, respiratory, and reproductive tracts. Multiciliogenesis requires activation of a specialized transcription program coupled to complex cytoplasmic events that lead to large-scale centriole amplification to generate multicilia. Yet, it remains unclear how these events are coordinated to initiate multiciliogenesis in epithelial progenitors. Here we identify an unsuspected mechanism orchestrated by the transcription factor E2f4 essential to integrate these processes. We show that after inducing a transcriptional program of centriole biogenesis, E2f4 translocates to the cytoplasm to become a core component of structures classically identified as fibrous granules (FG), acting as organizing centers for deuterosome assembly and centriole amplification. Remarkably, loss of cytoplasmic E2f4 prevents FG aggregation, deuterosome assembly and multicilia formation even when E2f4s transcriptional function is preserved. Moreover, in E2f4-deficient cells multiciliogenesis is rescued only if both nuclear and cytoplasmic E2f4 activities are restored. Thus, E2f4 integrates previously unrelated nuclear and cytoplasmic events of the multiciliated cell program.
Cytoplasmic E2f4 forms organizing centres for initiation of centriole amplification during multiciliogenesis.
Specimen part
View SamplesCompared to other fish models, miRNAs are currently most extensively studied and identified in zebrafish. Approximately 415 dre-miRNAs have been identified and several articles have studied some aspect of miRNA function in zebrafish such as their role in basic development and in disease pathways. However, this field of research is in its infancy and the function of several dre-miRNAs, as well as their tissue-specific expression profile, are yet to be defined. In this study, the liver and gut were dissected (wildtype/untreated fish), total and small RNA were extracted, mRNA and miRNA libraries constructed and subjected to high throughput sequencing (HTS) using standard approaches. We carried out differential expression (DE) analysis and compared liver miRNA expression to gut using established bioinformatics pipelines. Through bioinformatics analysis, known and putative novel miRNAs were identified. Finally, we constructed a “miRNA matrix” that connects both total RNA-Seq and miRNA-Seq. Overall design: Examination of transcriptome in an in vivo model organism in two defined tissues, liver and gut.
Interplay Between MicroRNAs and Targeted Genes in Cellular Homeostasis of Adult Zebrafish (<i>Danio rerio</i>).
Sex, Specimen part, Subject
View SamplesExposure to bisphenol A (BPA), an endocrine disruptor (ED), has raised concerns for both human and ecosystem health. Epigenetic factors, including microRNAs, are key regulators of gene expression during cancer. The effect of BPA exposure on the zebrafish epigenome remains poorly characterized. Zebrafish represents an excellent model to study cancer as the organism develops disease that resembles human cancer. Using zebrafish as systems toxicology model, we hypothesized that chronic BPA-exposure impacts the miRNome in adult zebrafish and establishes an epigenome more susceptible to cancer development. After a 21 day exposure to 100 nM BPA, RNA from the liver was extracted to perform high throughput mRNA and miRNA sequencing. Differential expression (DE) analyses comparing BPA-exposed to control specimens were performed using established bioinformatics pipelines. In the BPA-exposed liver, 6,188 mRNAs and 15 miRNAs were differently expressed (q = 0.1). By analyzing human orthologs of the DE zebrafish genes signatures associated with non-alcoholic fatty liver disease (NAFLD), oxidative phosphorylation, mitochondrial dysfunction and cell cycle were uncovered. Chronic exposure to BPA has a significant impact on the liver miRNome in adult zebrafish and has the potential to cause adverse outcomes including cancer. Overall design: Examination of transcriptome changes in an in vivo model organism exposed to a common, environmental compound.
The Plasticizer Bisphenol A Perturbs the Hepatic Epigenome: A Systems Level Analysis of the miRNome.
No sample metadata fields
View SamplesThe cellular response to genotoxic stress is mediated by a well-characterized network of DNA surveillance pathways. The contribution of posttranscriptional gene regulatory networks to the DNA damage response (DDR) has not been extensively studied. Here, we systematically identified RNA-binding proteins differentially interacting with polyadenylated transcripts upon exposure of human breast carcinoma cells to ionizing irradiation (IR). Interestingly, more than 260 proteins including many nucleolar proteins showed increased binding to poly(A) RNA in IR-exposed cells. The functional analysis of DDX54, a candidate genotoxic stress responsive RNA helicase, revealed that this protein is an immediate-to-early DDR regulator required for the splicing efficacy of its target IR-induced pre-mRNAs. Upon IR exposure, DDX54 acts by increased interaction with a well defined class of pre-mRNAs which harbor introns with weak acceptor splice sites, as well as by protein-protein contacts within components of U2 snRNP and spliceosomal B complex, resulting in lower intron retention and higher processing rates of its target transcripts. Since DDX54 promotes survival after exposure to IR its expression and/or mutation rate may impact DDR-related pathologies. Our work indicates the relevance of many uncharacterized RBPs potentially involved in the DDR. Overall design: Gene expression profiling of MCF-7 cells upon DDX54 knockdown exposed to ionizing radiation
DDX54 regulates transcriptome dynamics during DNA damage response.
Specimen part, Cell line, Subject, Time
View SamplesCancer-associated skeletal muscle fatigue is a common problem in clinical oncology that is often associated with cancer cachexia, but is not exclusively observed in cachectic patients. The majority of breast cancer (BC) patients report muscle fatigue despite cachexia being relatively rare in this patient population. The clinically relevant phenotype of muscle fatigue in the absence of frank cachexia has no established model system and no approved therapeutic agents. Here, we utilize a breast cancer patient-derived orthotopic xenograft (BC-PDOX) model to recapitulate the human phenotype of tumor-induced muscle fatigue without muscle wasting, and utilized RNA-sequencing to identify pathways contributing to this clinically common phenomenon.
Human Breast Cancer Xenograft Model Implicates Peroxisome Proliferator-activated Receptor Signaling as Driver of Cancer-induced Muscle Fatigue.
Sex, Specimen part
View SamplesPARK2 (PARKIN) is an E3 ubiquitin ligase whose dysfunction has been associated with the progression of Parkinsonism and human malignancies, and its role in cancer remains to be explored. In this study, we investigated its role in glioma.
Genomic and Functional Analysis of the E3 Ligase PARK2 in Glioma.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
ZNF750 is a lineage-specific tumour suppressor in squamous cell carcinoma.
Cell line
View SamplesCDK4/6 kinase inhibitors have shown great promise in clinical trials in various cancer types and have recently entered clinical trial for advanced prostate cancer. Although patients are expected to respond well to this class of drugs, development of resistance in some patients is anticipated. To pre-empt this and study how prostate cancer may evade CDK4/6 inhibition, new resistance models were generated from LNCaP and LAPC4 prostate cancer cells cells by prolonged culturing in presence of 0.5uM palbociclib. RNA sequencing data was integrated with phospho-proteomics to unravel the molecular underpinnings of acquired resistance to palbociclib and resultant broad CDK4/6 inhibitor resistance. Overall design: Thirty total sample: three biological replicates of vehicle control and PD treated parental and Palbociclib (PD) resistant cells (PDR) that were generated from LAPC4 and LNCaP cells.
MAPK Reliance via Acquired CDK4/6 Inhibitor Resistance in Cancer.
Specimen part, Subject
View Samples